Some electrical components are formed from a copper ribbon having a centrally positioned narrower strip of solder extending longitudinally thereon. The common method currently used for manufacturing such a product is to place a solder ribbon on a copper ribbon that is wider than the solder ribbon and melt the solder ribbon onto the copper ribbon. The molten solder is then allowed to solidify and bond thereon. When the solder ribbon melts, the molten solder tends to flow uncontrollably so that the overall dimensions and surface finish of the resulting solder layer are inconsistent. In order to provide a copper ribbon product that has a dimensionally consistent layer of solder thereon, the layer of solder must then be machined to the desired dimensions. A drawback of this method is that it wastes material, it is inefficient, and fairly expensive.
The present invention is directed to an apparatus and method for forming a metallic profile on a strip of material in an efficient and cost effective manner. The present invention is directed to an apparatus for casting molten metal onto a moving strip of material including a stationary die having upstream and downstream portions with a casting portion, past which the strip of material is capable of being moved. The casting portion has a casting channel extending from the upstream portion through the downstream portion for facing the moving strip for containing and shaping the molten metal into a profile against the moving strip. A heating arrangement heats the upstream portion of the stationary die to prevent the molten metal from solidifying within the casting channel at the upstream portion, thereby allowing the molten metal to fill the casting channel. The casting channel at the downstream portion allows the molten metal to cool while passing therethrough to solidify sufficiently to retain the shape of the casting channel when exiting the stationary die.
In preferred embodiments, the moving strip is a metallic strip and the molten metal is molten solder. A preheating station preheats the moving strip prior to casting the molten metal thereon. The heating arrangement on the upstream portion of the stationary die includes at least one heating device. A cooling system cools the downstream portion of the stationary die and may be a recirculating fluid cooling system. The casting portion of the stationary die is adapted to abut the moving strip such that the casting channel of the stationary die and the moving strip define the profile of the cast metal therebetween. A guide channel is formed in the casting portion of the stationary die for guiding the moving strip therethrough in relation to the casting channel. The moving strip is held against the casting portion by a support portion of the stationary die. A reservoir for containing a supply of molten metal is formed in the stationary die in communication with the casting channel. The reservoir and the casting channel are connected by a tapering transition region. A delivery conduit delivers molten metal to the reservoir and the stationary die. A heated chamber stores the molten metal and supplies the delivery conduit with the molten metal which is pumped through the delivery conduit by a pumping device.
The present invention is also directed to a stationary die for casting molten metal onto a moving strip of material including a reservoir for containing molten metal. The stationary die also includes a casting channel having casting surfaces for containing and shaping the molten metal into a profile against the moving strip. A tapering transition region connects the reservoir to the casting channel, wherein the reservoir, the transition region and the casting channel are longitudinally aligned and configured to face the moving strip.
The present invention is further directed to a method of casting molten metal onto a moving strip of material including moving the strip of material past a stationary die having upstream and downstream portions. A casting channel faces the moving strip and extends from the upstream portion through the downstream portion. The molten metal is contained and shaped into a profile against the moving strip with the casting channel. The upstream portion of the stationary die is heated to prevent the molten metal from solidifying within the casting channel at the upstream portion, thereby allowing the molten metal to fill the casting channel. The molten metal is allowed to cool while passing through the casting channel at the downstream portion to solidify sufficiently to retain the shape of the casting channel when exiting the stationary die.
The present invention is able to manufacture a ribbon of material having a profiled layer of metal thereon in a manner where the profile does not have to be later machined in an additional process. This saves material, time and labor and it therefore costs less to produce such a product in a manner according to the present invention than with the common prior method.